The present invention relates to novel chromene materials having a nitrogen heteroatom. More particularly, this invention relates to materials of pyrano[3,2-c]quinoline structure and/or of pyrano[3,2-c]quinolinone structure and to compositions and photochromic articles comprising photochromic materials of these structures. When exposed to light radiation containing ultraviolet rays, such as the ultraviolet radiation in sunlight or the light of a mercury lamp, many photochromic materials exhibit a reversible change in color. When the ultraviolet radiation is discontinued, such a photochromic material will return to its original color or colorless state.
Various classes of photochromic materials have been synthesized and suggested for use in applications in which a sunlight-induced reversible color change is desired. Although polycyclic aromatic hydrocarbon materials having a nitrogen heteroatom are known, there is a need for such materials that can demonstrate a range of photochromic performance properties.